smbspool_krb5_wrapper is a tool that can be used to print using Kerberos credentials. To get this working smbspool_krb5_wrapper needs to be the smb backend of CUPS. It needs to be owned by root and the permissions for the binary need to be 0700. Once smbspool_krb5_wrapper switched to the user trying to print it executes smbspool. It should not be called by a user.